The use of cover crops has gained popularity in many different agricultural practices in recent years. In general, a cover crop is a crop planted in order to provide benefits for the production of a main crop (sometimes referred to as a “cash crop”), rather than being produced for sale or harvest. Benefits may include management of soil fertility, soil quality, water, weeds, pests, diseases, erosion, and so forth. Cover crops are therefore sometimes referred to as “green manure.” Cover crop species encompass many legumes, grasses, other non-legumes, and mixtures thereof, and are typically selected based on a number of factors, including growth pattern, relative vigor (as compared with the main crop, for example), root system characteristics, nitrogen contribution to the soil, the main crop species with which the cover crop is used, and so forth.
Often, cover crops are grown for a specific period, then terminated in order to improve soil fertility and quality for a main crop, such as by contributing biomass to the soil, reducing or eliminating competition for the main crop for nutrients and moisture in the soil, and so forth. A popular method of cover crop termination is by tilling, or plowing under, the cover crop before it is allowed to reach full maturity. In many agricultural practices, the main crop is then planted in the tilled soil.
In some applications, such as in vineyards and orchards, a cover crop is used alongside an existing main crop, such as in the soil between rows of grape vines or trees. In such applications, termination of the cover crop is often timed in order to provide (and/or reduce competition for) nutrients and moisture in the soil, prior to or during one or more growth phases of the main crop, even though the cover crop soil is generally not immediately re-used for planting. Such discontinuous use of the cover crop soil increases erosion concerns during periods in which the soil is bare, such as between termination and replanting.
Although tilling provides additional benefits such as soil aeration, as a method of cover crop termination, tilling involves expending significant resources, such as labor and fuel costs required for multiple passes with a tilling implement in order to sufficiently break down the soil. In addition, tilling may result in loss of a beneficial organic layer, and, in applications in which the main crop is not planted in the same soil, increase erosion during periods when the soil is bare. Tilling also requires what may be a considerable re-seeding cost when replacing or replanting the terminated cover crop. Other methods of cover crop termination, such as flattening and/or crimping with a studded or banded roller, involve similar costs.